Mobile Ad Spending Tops $4B In '12

US Mobile Ad Spending Tops $4B in 2012: The effectiveness of mobile advertising is still being debated, but media buyers are already going all-in while also increasing their presence on the Web. Mobile ad spending grew 180 percent to top $4 billion in 2012, according to the latest estimates from digital marketing research firm eMarketer. At the same time, the Interactive Advertising Bureau and PwC US report Internet ad revenues totaled $9.3 billion for the third quarter.